Module 10 - 2 Flashcards
What is the direction of nucleic acid strands?
5’->3’
How does RNA differ from DNA
RNA contains ribose rather than deoxyribose, uracil rather than thymine, and single stranded but can adopt the complex 3 dimensional structures
What is the function of ribosomal RNA (rRNA)?
Integral part of ribosomes, ~80% of RNA in cells.
What is the function of transfer RNA (tRNA)?
Carry activated amino acids to ribosomes for protein synthesis. (small molecules 73-95 nucleotides long).
What is the function of messenger RNA (mRNA)?
Code for proteins. contains triplet codons that specify the amino acid sequence of a protein.
What is the function of micro RNA (miRNA)?
Are short oligonucleotides (22-24 nts in length) that function in transcriptional and post-transcriptional regulation of gene expression.
Why is DNA more stable than RNA?
The 2’ hydroxyl group of RNA increases susceptibility to base hydrolysis at the phosphodiester linkage
why is it important that DNA is more stable?
because it is a long term information storage molecule
Why is the double Helix model important
Explain all the known experimental data and predicted the mechanism for storing and replicating the genetic information
What showed that DNA is a double helix?
X-ray diffraction data
Explain the structure of DNA?
Two helical DNA strands coiled around a common axis forming a right-handed double helix
In what direction do the strands of the double helix run?
Opposite directions
What is the structure of DNA strands?
Complimentary with sugar-phosphate backbones on the outside and nitrogenous bases on the inside.
How are base pairs oriented in the double helix?
They are perpendicular to the helix axis
What is Watson-Crick base pairing?
Matching a purine with a pyrimidine.
